DRVSPACE /COMPRESS

Compresses the files on an existing hard disk drive, floppy disk, or other
removable media. Compressing an existing drive makes more space available on
that drive.

Note: DriveSpace cannot compress a drive that's completely full. To
      compress your startup hard disk drive, the drive must contain at
      least 1.2 MB of free space. Other hard disk drives and floppy disks
      must contain at least 1.1 MB of free space. (DriveSpace cannot
      compress 360K floppy disks.)

Syntax

    DRVSPACE /COMPRESS drive1: [/NEWDRIVE=drive2:] [/RESERVE=size] [/F]

Parameter

drive1:
    Specifies the existing drive you want to compress.

Switches

/COMPRESS
    Compresses the hard disk drive or floppy disk specified by the drive
    parameter. This switch can be abbreviated to /COM.

/NEWDRIVE=drive2:
    Specifies the drive letter for the uncompressed (host) drive. After
    DriveSpace compresses an existing drive, your system will include both
    the existing drive (now compressed) and a new uncompressed drive. The
    /NEWDRIVE switch is optional; if you omit it, DriveSpace assigns the
    next available drive letter to the new drive. This switch can be
    abbreviated to /NEW.

/RESERVE=size
    Specifies how many megabytes of space to leave uncompressed. Because
    some files, such as the Windows swap file, do not work properly when
    stored on a compressed drive, it's a good idea to reserve some
    uncompressed space. The uncompressed space will be located on the new
    uncompressed drive. (If the drive you are compressing contains a Windows
    permanent swap file, DriveSpace moves the file to the new uncompressed
    drive.) This switch can be abbreviated to /RES.

/F
    Prevents DriveSpace from displaying the final screen when compression is
    complete. This screen includes compression statistics. If you specify
    the /F switch, DriveSpace returns to the command prompt when compression
    is complete.